This video 'Evolution of Dance' is the all time Most Viewed video on YouTube with 25,092,279 views at the time of writing this post. The next most viewed video had only half as many views — 12,584,122! If you see the two videos, the first is a 'performance-based-entertainment' piece, while the second is a 'spoofy-video' on the Pokemon theme song. But why such a huge difference in views?

The answer to that is what I shall indulgently christen the 'leader-feeder effect'. Which states that:

In a democratically evaluative framework, given two equally performing contenders, the one who takes the lead gets fed by a greater number of patrons (whose behaviour is in conformance with the zeitgeist), leading to an exponential difference between their performance metrics, thereafter.

In fact, if you see the views for the videos ranked after these, they tend to 'even-out'. So the videos ranked third, fourth, fifth and so on, do not have such a huge magnitude of difference between them. Now hypothetically, if YouTube were to remove these top two videos, the video currently ranked third, will see an exponential rise in the views it gets, and end up having a much bigger lead. Similarly, the next in line video will also see a rise in views under the diminishing leader-feeder effect.

Disclaimer: In case there is already some theory/postulate/model in economics that addresses this phenomenon — I haven't read it! And if you don't trust me, and would like to go along with 'that original research' — you just provided empirical evidence for my 'leader-feeder effect'. Q.E.D

Related (but hopelessly out-of-scale) trivia:
At last count, my video Brokeback Claymation on YouTube (which you can also see here) had 569.000 views (Oh yeah that's a decimal in between!)